The cowls have the same footprint, as the fuselages are the same, but the inlets are different. The Edge has a spinner ring and two air inlets
The Extra has a cressent opening and no spinner ring. (the pic below is an Extreme Flight, but you can see that it is an Extra cowl)
The Extra cowl also has louvers moulded in, the Edge does not.
Thanks for looking guys!
Jon